A deadly combination of warmer weather and less rainfall in Mexico and its southern neighbors will devastate yields of traditional crops like corn and beans, as well as the region's coffee harvest, according to two studies.

Mexico stands to lose between a quarter and a third of its agricultural production by 2080, according to a study by William Cline of the Washington, D.C.-based Center for Global Development. That is more than any country besides India. Central America will see agricultural output shrink between 12 and 24 percent, according to Cline, a loss cushioned by the region's average rainfall of 6 millimeters per day, compared with Mexico's 2 millimeters per day.

"The fundamental problem is that water needs will go up as the heat rises, but unfortunately, these countries will be getting less water," Cline said.

Land suitable for coffee growing in parts of Central America is expected to shrivel by up to 80 percent by 2050, one of the micro-forecasts published this year said. To head off the slow-motion catastrophe, the region's governments are investing millions of dollars in the development of better seeds and better-trained farmers, among other things.